WASHINGTON (AP) — The White House abruptly announced Monday that it had scuttled plans to hold the upcoming G-8 economic summit in Chicago, and would instead host world leaders at the presidential retreat at Camp David in Maryland.

It was an unusually late location change for a large and highly scripted international summit and came with little explanation from the White House. Chicago Mayor Rahm Emanuel — the former White House chief of staff who personally lobbied President Barack Obama to hold the summit in Chicago — was informed only hours before the official announcement.

White House national security spokesman Tommy Vietor simply said that Camp David, the rustic retreat in the mountains of Maryland, was a setting that would allow for more intimate discussions among the G-8 leaders. He said security and the possibility of protests were not factors in the decision, noting that Obama would still host the NATO summit in his hometown of Chicago from May 20-21.

The White House said the G-8 summit would take place May 18-19.

The White House announced plans last summer to hold both summits back-to-back in Chicago, giving the president a high-profile opportunity to tout his foreign policy and diplomatic credentials on his home turf in an election year.

The idea of moving the G-8 to Camp David was raised to the president a few weeks ago, a senior administration official said, adding that the president was intrigued by the novelty of the idea and asked staff whether they could pull off the change.

The official who spoke on condition of anonymity about internal White House thinking.

Adding to the curious nature of the White House announcement was the fact that Obama rarely spends time at his presidential retreat. And unlike many of his predecessors, Obama has never hosted a world leader at Camp David.

Monday’s announcement appeared to catch many in Chicago by surprise. Click HERE for reaction and continuing coverage.

A spokeswoman for Emanuel said the Chicago mayor was informed about the location change in a Monday phone call from a White House official.

Chris Johnson, spokesman for the Chicagoland Chamber of Commerce, said his organization was “just as surprised about the announcement as anybody else.”

The world’s eight largest economies are represented in the G-8 and hosting duties for the annual summit are rotated among the member countries. The summits have become a target for large, and sometimes violent, protests in recent years, making security costs a concern for host cities.

At least one protest group heralded the news as a major victory. But Joe Iosbaker of the United National Antiwar Committee in Chicago said protests would still go on during the NATO summit.

Chicago officials began planning for the summits last summer, with city officials predicting it would give the city a chance to shine internationally, while the police rank-and-file worryied whether they would be prepared to handle the thousands of protesters expected to converge downtown.

Elizabeth Sherwood-Randall, Obama’s senior director for European affairs, said recently that the president was confident his hometown could put on a “great show” and that its police department was up to the task of providing security.

The city’s host committee had estimated it could cost $40 million to $65 million to stage the events, including the costs for security.

Gordon Johndroe, who served as National Security Council spokesman for President George W. Bush, said the immense logistics involved in setting up an international gathering like the G-8 would make it difficult to split the summits at such a late date.

“It is very complicated to set these things up, and even more complicated to move them that quickly,” said Johndroe.

Leaders from Canada, France, Germany, Italy, Japan, Russia, the United Kingdom, as well as the European Union, are expected to attend this year’s gathering.